Lean idle. Rich cruise.

No wonder Holleys run rich. Carter carbs DO run a restriction to the T slot. Carter called it the 'Economizer' [ & patented it ] for obvious reasons. In many TQs I have checked, it varies from 0.046" to about 0.052". Another name for this restriction is the Idle Down Channel. In the Ruggles QJ book, he gives examples of sizing from std engines to fully modified: 0.040" to 0.055".